In modern electronics, low power consumption and small size are a design priority.
One of the ways that power consumption and volume may be reduced is to minimize the number of components used. However, existing circuit arrangements typically require separate components for separate functions. For example, wireless transceivers may require an active amplifier for amplification and a separate active filter for filtering.
One of the ways to reduce the number of components is to use the same components for different functions. For example, a wireless transceiver may use a single active amplifier for both amplification and filtering, thereby reducing the number of components required.
Using a single active amplifier for both amplification and filtering is suitable for circuit arrangements in which the gain and cutoff frequency characteristics are static. However, this arrangement suffers from the disadvantage of being unsuitable for circuit arrangements where the gain or the cutoff frequency characteristics are required to be configurable. For example, by using a single active amplifier for both amplification and filtering, changing the gain of the amplifier will necessarily affect the cutoff frequency and visa versa.
To overcome this problem, existing circuit arrangements resort to using separate active amplifiers such that the configuration of the gain of the first amplifier does not affect the cutoff frequency of the second amplifier. However, this arrangement suffers from the disadvantage of consuming more power and having a larger size.
A need therefore exists to overcome, or at least ameliorate, the disadvantages of existing arrangements.